Heterologous expression of five disulfide-bonded insecticidal spider peptides

Spider-Venom Peptides: Structure, Bioactivity, Strategy, and Research Applications

Spiders (Araneae), having thrived for over 300 million years, exhibit remarkable diversity, with 47,000 described species and an estimated 150,000 species in existence. Evolving with intricate venom, spiders are nature's skilled predators. While only a small fraction of spiders pose a threat to humans, their venoms contain complex compounds, holding promise as drug leads. Spider venoms primarily serve to immobilize prey, achieved through neurotoxins targeting ion channels. Peptides constitute a major part of these venoms, displaying diverse pharmacological activities, and making them appealing for drug development. Moreover, spider-venom peptides have emerged as valuable tools for exploring human disease mechanisms. This review focuses on the roles of spider-venom peptides in spider survival strategies and their dual significance as pharmaceutical research tools. By integrating recent discoveries, it provides a comprehensive overview of these peptides, their targets, bioactivities, and their relevance in spider survival and medical research.

Venoms with oral toxicity towards insects

Animal venoms are a promising source of potential bioinsecticides. To find hits with pronounced oral insect toxicity, we screened 82 venoms using Achroia grisella (Lepidoptera) and Tenebrio molitor (Coleoptera) larvae, and adult Drosophila melanogaster (Diptera). We also injected the most potent venoms in adult D. melanogaster to compare their efficiency in different routes of administration. 18 venoms from spiders and snakes show high oral toxicity and can be further exploited to isolate new insecticides.

Heterologous Expression of an Insecticidal Peptide Obtained from the Transcriptome of the Colombian Spider Phoneutria depilate

Spider venoms are composed, among other substances, of peptide toxins whose selectivity for certain physiological targets has made them powerful tools for applications such as bioinsecticides, analgesics, antiarrhythmics, antibacterials, antifungals and antimalarials, among others. Bioinsecticides are an environmentally friendly alternative to conventional agrochemicals. In this paper, the primary structure of an insecticidal peptide was obtained from the venom gland transcriptome of the ctenid spider Phoneutria depilata (Transcript ID PhdNtxNav24). The peptide contains 53 amino acids, including 10 Cys residues that form 5 disulfide bonds. Using the amino acid sequence of such peptide, a synthetic gene was constructed de novo by overlapping PCRs and cloned into an expression vector. A recombinant peptide, named delta-ctenitoxin (rCtx-4), was obtained. It was expressed, folded, purified and validated using mass spectrometry (7994.61 Da). The insecticidal activity of rCtx-4 was demonstrated through intrathoracic injection in crickets (LD50 1.2 μg/g insect) and it was not toxic to mice. rCtx-4 is a potential bioinsecticide that could have a broad spectrum of applications in agriculture.

Versatile spider venom peptides and their medical and agricultural applications

Spiders have been evolving complex and diverse repertoires of peptides in their venoms with vast pharmacological activities for more than 300 million years. Spiders use their venoms for prey capture and defense, hence they contain peptides that target both prey (mainly arthropods) and predators (other arthropods or vertebrates). This includes peptides that potently and selectively modulate a range of targets such as ion channels, receptors and signaling pathways involved in physiological processes. The contribution of these targets in particular disease pathophysiologies makes spider venoms a valuable source of peptides with potential therapeutic use. In addition, peptides with insecticidal activities, used for prey capture, can be exploited for the development of novel bioinsecticides for agricultural use. Although we have already reviewed potential applications of spider venom peptides as therapeutics (in 2010) and as bioinsecticides (in 2012), a considerable number of research articles on both topics have been published since, warranting an updated review. Here we explore the most recent research on the use of spider venom peptides for both medical and agricultural applications.

Successful refolding and NMR structure of rMagi3: A disulfide-rich insecticidal spider toxin

The need for molecules with high specificity against noxious insects leads the search towards spider venoms that have evolved highly selective toxins for insect preys. In this respect, spiders as a highly diversified group of almost exclusive insect predators appear to possess infinite potential for the discovery of novel insect-selective toxins. In 2003, a group of toxins was isolated from the spider Macrothele gigas and the amino acid sequence was reported. We obtained, by molecular biology techniques in a heterologous system, one of these toxins. Purification process was optimized by chromatographic methods to determine the three-dimensional structure by nuclear magnetic resonance in solution, and, finally, their biological activity was tested. rMagi3 resulted to be a specific insect toxin with no effect on mice.

Toxin Fused with SUMO Tag: A New Expression Vector Strategy to Obtain Recombinant Venom Toxins with Easy Tag Removal inside the Bacteria

Many animal toxins may target the same molecules that need to be controlled in certain pathologies; therefore, some toxins have led to the formulation of drugs that are presently used, and many other drugs are still under development. Nevertheless, collecting sufficient toxins from the original source might be a limiting factor in studying their biological activities. Thus, molecular biology techniques have been applied in order to obtain large amounts of recombinant toxins into Escherichia coli. However, most animal toxins are difficult to express in this system, which results in insoluble, misfolded, or unstable proteins. To solve these issues, toxins have been fused with tags that may improve protein expression, solubility, and stability. Among these tags, the SUMO (small ubiquitin-related modifier) has been shown to be very efficient and can be removed by the Ulp1 protease. However, removing SUMO is a labor- and time-consuming process. To enhance this system, here we show the construction of a bicistronic vector that allows the expression of any protein fused to both the SUMO and Ulp1 protease. In this way, after expression, Ulp1 is able to cleave SUMO and leave the protein interest-free and ready for purification. This strategy was validated through the expression of a new phospholipase D from the spider Loxosceles gaucho and a disintegrin from the Bothrops insularis snake. Both recombinant toxins showed good yield and preserved biological activities, indicating that the bicistronic vector may be a viable method to produce proteins that are difficult to express.